Wiring through firewall

I searched! So I hope I can get some knowledge and also save a few dollars having an install done.

If I slit the main boot that goes through the firewall of my 3rd gen and run my wires through there, will my wire run down to where the wires come out in the cab down by your left foot? I was wondering if that boot went all the way down to the other side or if just acted like a grommet.
Or will I have to cut the carpet and fish the wires out somewhere?

Also, theres a pre made hole on the drivers side top of the engine bay, anyone ever use that one to run wires? I took out the plug and all I can see is carpet.

Im wiring ditch lights.

Thanks!

 

I just went through the boot in the firewall. The Main one on the driver's side

 

^me too.

 

Just punch a hole through with a small phillips head screw driver, you'll be able to see where it comes out on the drivers side. It goes straight through, no cutting necessary.

 

There is an accessory nipple under the main bundle that I used. Get a flashlight and look under the big bundle. It's empty from the factory. Just snip off the tip to use. It's about the diameter of a sharpie.

 

How’d you snip off the tip? Or do you guys recommend to poke a hole instead?

 

It can be difficult to snip the tip, just drive a thick wire through or cut a little hole in the boot. Seal with silicone if you’re concerned about the size but it stays pretty tight.

The carpet in the area folds back so you won’t have to cut it, fold it over to open, do your work, fold it back over to close it back up. You’ll see why I mean when you get in there

 

I used the boot where to two aluminum 9AC?) lines run through the firewall, right in behind the fuse box area. This truck was the easiest one I ever had to get wires from the bay to under the dash. I didn’t punch a hole or anything, just pushed real hard on my wires and they were inside in no time.

 

I got my tip snipped right after birth. Also, was born with the hole so no need to poke a new one.

 

Get a piece of polyethylene tubing from home depot, the hard stuff. Pro tip - it also makes running speaker wires through door boots easier. Quick spray of dry lube, wires pull right through. Then you pull the tubing off the wire. No mess, no poking sharpened wire through and possibly hitting something else. Takes a minute what used to take much longer.

 

Coat hanger works well and I'm pretty sure has been the DIY standard for as long as mods have existed.

 

I have a kit for car stereo installs, and I can never find a hanger (the wife moved to plastic for some reason). I hated pulling a hanger through, because I would need to pinch with pliers or tape the cable on and it always pulled off coming through the boot. I've never looked back with tubing.

 

wire hanger worked for me too.

 

tubing wouldn't cut it to get my big old switchpro wire and connector through, or my HAM cables.

 

This is what I did and used the hole from the engine bay that has the hood latch release cable going through it and yes on the inside it is covered by a 3 way cut carpet inlet on the inside

 

I've basically had to slice a hole in my grommet big enough for 3 fingers to get through.

Switchpro panel cable in sheath
HAM VHF/UHF cable x 2
HAM UHF SATCOM coax x 2
Ham power cables
siren controller power
Brake signal wire
I'm sure I am forgetting a few.

 

I didn't have the necessary items to do so or I would have.

 

Yeah with all the wiring already being routed through from factory, its definitely a tight squeeze.

 

Rather than punching a hole in the fabric of the firewall I did a little fishing from the small driver side passthrough, between the fabric and firewall to the main passthrough where on the inside you will see the fabric is slotted to peel back so the fishing can begin and end to the main fuse box.

 

I used a fiberglass electricians fishing rod to run the wires through the factory grommet in the firewall.
like this one: I like those rods bc they are stiff with a good amount of flexibility instead of a wire hanger or fish tape.